Answer: C
An axe is a mechanical device with two inclined planes, thick at one end and tapers to a thin edge and when it is used to chop wood, the axe blade acts as a wedge and changes the direction of the input force. When the axe blade penetrates the wood, a portion of the downward force of the blade is changed to sideways forces, which are perpendicular to each external of the blade and the sideways forces cause the wood to split in contrasting directions.